1. Field of the Invention
This invention relates to door mounting hardware and in particular to a door hinge capable of facilitating electrical connection with hardware such as electric locks carried in the door.
2. Description of Related Art
The term “electric hinge” as used in the door hardware industry refers to a door, panel or window hinge which carries wires to transfer electrical power and/or information between the surrounding wall or frame and hardware carried on the door, such as electric locks, closers, openers and sensors. An electric hinge 20′ according to the prior art as shown in FIG. 1 installs wires through small diameter holes 26′, 28′ that have been drilled within the thickness of and through the entire width of the hinge leaf or plate. The wiring hole ends at a hinge knuckle 22′, typically at an end knuckle of one of the pair of hinge plates, so that the wires can pass through the pin hole in a knuckle on one plate of the hinge pair to the pin hole in an adjacent knuckle on the other hinge plate. The wiring holes generally extend at an angle to the hinge plate edge and centerline of the hinge pin to permit the wiring hole to avoid passing through a hinge plate mounting hole 60. Since the wiring hole must have a diameter significantly smaller than the thickness of the hinge, typically less than 0.10 in. (2.5 mm), the wiring holes require precise drilling or fixturing. A drill bit 8 which has a relatively large length to diameter ratio tends to walk when first contacting the edge of the hinge 21′. In addition, the removal of scrap chips from the drilling process through the entire width of the hinge plate also tends to be more difficult, taking extra time in the drilling procedure. Additionally, fishing the wires through the wiring hole becomes more difficult through longer wiring holes, especially considering that four wires may be required in each hole. Wires which include twisted pairs or twisted wire groups may make the running of the wires even more arduous. A process is needed for more efficiently drilling the wiring holes and running the wires through the hinge so that an electrical connection can be made from hardware in the door to hardware outside of the door, such as in the frame or other location.